The debate over fresh water poses a conundrum for many New Zealanders - iwi and hapu, politicians at the national and regional level, and communities around the country. Is fresh water a commodity, to be bought and sold, or is it part of the birthright of all Kiwis? Do iwi and hapu have property rights in fresh water, or use rights? What kinds of rights in fresh water do other New Zealanders enjoy?
There are intriguing ironies in this discussion. When Te Tiriti o Waitangi was signed, for example, Maori had no concept of wai maori (fresh water) as a commodity. Instead, it was the life blood of the land. In a curious twist, some Maori leaders now argue that their kin groups have property rights in fresh water, while the Prime Minister is adamant that no one owns this resource.
Like most New Zealanders, Maori and non-Maori, I think that fresh water belongs to a "common pool" of resources (although what this might mean in te ao Maori - the Maori "world" - is very different from what it might mean in the law).
The question, then, is about relationships to particular waterways, and how the use rights of Maori and other New Zealanders might be allocated and protected.
Hanging over this debate is the question of asset sales. Should the rights to use fresh water to generate energy be alienated to private owners? If so, what happens to the relationships that New Zealanders, including iwi and hapu, have with their waterways?
Will Kiwis find themselves excluded from some creeks and rivers, and unable to compete for access to fresh water, or to influence the prices charged for the energy generated? What about the downstream effects of power generation?
In trying to answer such questions, the Nobel Prize winner Elinor Orstrom examined long-term regimes for the use of "common pool" resources in many countries - including fresh water, forests and fisheries. She discovered a set of features shared by successful use regimes.
First, they have clear rules around rights of access and management. Second, all of those involved in the use of the resource participate in setting the rules. Third, monitoring of the rules happens primarily at the local level, with fail-safe protections against abuses.
Fourth, there are clear sanctions for breaches to the rules, from early warnings to more severe penalties. Fifth, those that gain big benefits from the use of the resource pay the big costs involved.
According to Orstrom, such regimes rely above all on face-to-face dialogue and mutual trust. Such co-operative, grounded systems are more efficient and less wasteful than the top-down systems imposed by central government.
Where face-to-face communication is lacking, use regimes for "common pool" resources often break down. Here, a local example can illustrate how this happens. At the recent Transit of Venus Forum in Gisborne, serious concerns were raised about exotic forests in the region.
On the East Coast, pine plantations planted by successive New Zealand governments to protect fragile soils were privatised (against local advice) in the 1980s. These are now being clear-felled by their (mostly overseas) owners.
Although many of these forests are registered with the Forestry Stewardship Council in Bonn, FSC standards for sustainable management (including bush buffers around all waterways) are being ignored. Severe damage is caused to soils, waterways and fisheries, and to roads, culverts and bridges.
At the forum, local residents complained about environmental degradation, having to shoulder many of the costs, and their inability to talk directly with the overseas owners. In this case, Orstrom's rules for the effective management of such resources are being breached on a number of levels.
Without doubt, there are significant dangers when resources held in common are privatised. This is particularly the case when control over resources vital to community wellbeing is passed to remote owners, who avoid engagement with local citizens while profiting at their expense. In such situations, accusations of xenophobia are a red herring.
Fresh water is fundamental to human prosperity and survival, and risks should not be taken with its long-term management. If, as the Prime Minister argues, this is a resource held in common, then a clear and unambiguous expression of majority support for an alienation of use rights (not some generalised "mandate") is required.
Given widespread public opposition to the privatisation of access to fresh water, and Orstrom's findings about successful use regimes, authoritarian decision-making by politicians on this matter is both undemocratic and unwise.
Fresh water is the lifeblood of the land, and of the people who live here. It is a folly to sell the rights to its control.
* Dame Anne Salmond is professor of Maori studies at Auckland University and author of Bligh: William Bligh in the South Seas.